One process for the production of the infrared absorbing semiconductor material, Hg.sub.1-x Cd.sub.x Te, is termed MOCVD-IMP (Metalorganic Chemical Vapor Deposition-Interdiffused Multilayer Process). With this manufacturing process, alternating layers of CdTe and HgTe are grown with a total period thickness in the range of 20-120 nm (nanometers). After these layers have been grown by use of the MOCVD process, the group of layers are annealed which causes them to interdiffuse and form a homogeneous HgCdTe alloy. The mole fraction of the cadmium in the alloy is termed the "x" value, and this determines the wavelength of response for the infrared detector. This process is disclosed in U.S. Pat. No. 4,566,918 entitled "Utilizing Interdiffusion Of Sequentially Deposited Links Of HGTF And CDTE". This patent issued on Jan. 28, 1986.
With the conventional approach for manufacturing an interdiffused multilayer HgCdTe material, there is a maximum 0.33 percent mismatch in the lattice constants between the CdTe and the HgTe. This results in the production of strain at the interface. Although the individual layer thicknesses for the CdTe and the HgTe are thinner than the critical thickness for the onset of dislocation formation, there is still left a residual strain to accommodate for the weak, elastic constants of the HgTe and the underlying interdiffused HgCdTe. This mismatch in the lattice constants contributes to dislocation formation, which can be as high as 1-5.times.10.sup.6 cm.sup.-2.
A significant problem encountered in the design and use of semiconductor infrared detectors is that of dislocation defects in the HgCdTe alloy. These dislocations compromise the transport properties of the semiconductor, which in turn also reduce the performance of the HgCdTe infrared detectors. Furthermore, infrared detector devices requiring heterostructures with two or more dissimilar Hg.sub.1-x Cd.sub.x Te alloy compositions have additional misfit dislocations at the interfaces due to the different lattice constants. These dislocations also reduce the performance of HgCdTe detector structures with heterostructures and heterojunctions. Therefore, there is a need for a method of manufacture, and a resulting infrared sensitive material structure, which has a reduced defect density.